[Страдалецъ]

Я проверял, вполне работоспособный код.

Код:

unit Unit13;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm13 = class(TForm)
    Label1: TLabel;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form13: TForm13;

implementation

{$R *.dfm}

uses WinSock;

function GetLocalIP: String;
const WSVer = $101;
var wsaData: TWSAData;
    P: PHostEnt;
    Buf: array [0..127] of Char;
begin
 Result := '';
 if WSAStartup(WSVer, wsaData) = 0
 then begin
      if GetHostName(@Buf, 128) = 0
      then begin
           P := GetHostByName(@Buf);
           if P <> nil
           then Result := iNet_ntoa(PInAddr(p^.h_addr_list^)^);
           end;
      WSACleanup;
      end;
end;

procedure TForm13.FormCreate(Sender: TObject);
begin
 Label1.Caption := GetLocalIP
end;

end.

Код:

object Form13: TForm13
  Left = 0
  Top = 0
  Caption = 'Form13'
  ClientHeight = 302
  ClientWidth = 635
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  OnCreate = FormCreate
  PixelsPerInch = 96
  TextHeight = 13
  object Label1: TLabel
    Left = 16
    Top = 24
    Width = 31
    Height = 13
    Caption = 'Label1'
  end
end

Это тоже неработает?